1. Field of the Invention
This invention relates to gas turbine engine air cooled vane assemblies and, more particularly, to an improved method and replacement member for repairing such an assembly in the area of its leading edge.
2. Description of Prior Art
Vane assemblies used in the turbine section of gas turbine engines experience strenuous operating conditions including a combination of mechanical stresses and thermal stresses. Accordingly, such vane assemblies have been designed to be air cooled. A variety of such vane assemblies have been described in the art, one example of which is U.S. Pat. No. 3,628,880-Smuland et al patented Dec. 21, 1971 and assigned to the assignee of the present invention. These types of vane assemblies include a hollow interior portion enclosed by walls, some of which include openings to allow cooling air to exit from within the hollow interior of the vane assembly.
As can be appreciated, such vane assemblies are complex in design and are relatively costly to manufacture. Therefore, it is desirable to repair rather than to replace such vane assemblies which may have been worn or damaged during gas turbine engine operation. It has been recognized that a substantial portion of such wear or damage occurs at the leading edge wall and sometimes adjacent body portions of the airfoil of the vane assembly. Although repair of such vane portions have been made by fusion welding, such repair method has limitations because of distortion due to welding. In addition, recracking of the repair welds has been experienced in some instances.